1. Field of the Invention
The present invention relates to a secured apparatus and to a process for securing the transmission of documents by fax and a graphic code for the authentication of an image.
2. Description of Related Art
The positive points for faxing are simplicity of use, the use of the public telephone network and direct transmission. However, the main negative point is security. As a result of the latter a legal status has not been given to a document transmitted by facsimile or fax.
Most fax machines are in group 3 and do not operate in the error correction mode. These fax machines offer no integrity level. Deterioration can be due to printing, scanning or transmission noise or to deliberate acts of falsification. However, for a transmission by fax, the use of a signature of the exclusively electronic type on a bitmap file (scanned image) for checking the integrity cannot be envisaged. Thus, any transmission error modifies the signature. Moreover, the a posteriori non-repudiation of the document can then only take place if binary files are retained of the faxes received.
When two fax machines are used operating in the character mode, the use of an electronic signature is possible, because transmission then takes place in the error correction mode. However, the checking of the signature must take place manually using an adequate terminal, which constitutes a long and fastidious operation.
The object of the invention is to make more reliable the transmission of documents by fax, so as to prevent any a posteriori repudiation of a document sent. It also aims at permitting the authentication of an image or a document.